1. Field of the Invention
This invention relates to a process for the preparation of a pesticidal phenylacetate Y-rich enantiomer pair and to a novel crystalline X enantiomer pair.
2. Description of the Prior Art
U.S. Pat. No. 4,176,195 discloses an enantiomer pair consisting of S-.alpha.-cyano-3-phenoxybenzyl S-.alpha.-isopropyl-p-chlorophenylacetate and R-.alpha.-cyano-3-phenoxybenzyl R-.alpha.-isopropyl-p-chlorophenylacetate as a highly active pesticide and its preparation by crystallization or chromatography. U.S. Pat. No. 4,238,406 discloses a process for preparing this enantiomer pair or a mixture rich in this pair by precipitating crystals of the pair from the corresponding racemic mixture by seeding with crystals of the pair or of an isomer of the pair optionally in the presence of a basic catalyst. This enantiomer pair is referred to as the Y form.